release/src/router/mysql/libmysql/dll.c

   1 /* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation.
   6
   7    There are special exceptions to the terms and conditions of the GPL as it
   8    is applied to this software.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  18
  19 /*
  20 ** Handling initialization of the dll library
  21 */
  22
  23 #include <my_global.h>
  24 #include <my_sys.h>
  25 #include <my_pthread.h>
  26
  27 static my_bool libmysql_inited=0;
  28
  29 void libmysql_init(void)
  30 {
  31   if (libmysql_inited)
  32     return;
  33   libmysql_inited=1;
  34   my_init();
  35   {
  36     DBUG_ENTER("libmysql_init");
  37 #ifdef LOG_ALL
  38     DBUG_PUSH("d:t:S:O,c::\\tmp\\libmysql.log");
  39 #else
  40     if (getenv("LIBMYSQL_LOG") != NULL)
  41       DBUG_PUSH(getenv("LIBMYSQL_LOG"));
  42 #endif
  43     DBUG_VOID_RETURN;
  44   }
  45 }
  46
  47 #ifdef __WIN__
  48
  49 static int inited=0,threads=0;
  50 HINSTANCE NEAR s_hModule;       /* Saved module handle */
  51 DWORD main_thread;
  52
  53 BOOL APIENTRY LibMain(HANDLE hInst,DWORD ul_reason_being_called,
  54                       LPVOID lpReserved)
  55 {
  56   switch (ul_reason_being_called) {
  57   case DLL_PROCESS_ATTACH:      /* case of libentry call in win 3.x */
  58     if (!inited++)
  59     {
  60       s_hModule=hInst;
  61       libmysql_init();
  62       main_thread=GetCurrentThreadId();
  63     }
  64     break;
  65   case DLL_THREAD_ATTACH:
  66     threads++;
  67     my_thread_init();
  68     break;
  69   case DLL_PROCESS_DETACH:      /* case of wep call in win 3.x */
  70      if (!--inited)             /* Safety */
  71      {
  72        /* my_thread_init() */   /* This may give extra safety */
  73        my_end(0);
  74      }
  75     break;
  76   case DLL_THREAD_DETACH:
  77     /* Main thread will free by my_end() */
  78     threads--;
  79     if (main_thread != GetCurrentThreadId())
  80       my_thread_end();
  81     break;
  82   default:
  83     break;
  84   } /* switch */
  85
  86   return TRUE;
  87
  88   UNREFERENCED_PARAMETER(lpReserved);
  89 } /* LibMain */
  90
  91
  92 static BOOL do_libmain;
  93 int __stdcall DllMain(HANDLE hInst,DWORD ul_reason_being_called,LPVOID lpReserved)
  94 {
  95   /*
  96     Unless environment variable LIBMYSQL_DLLINIT is set, do nothing.
  97     The environment variable is checked once, during the first call to DllMain()
  98     (in DLL_PROCESS_ATTACH hook).
  99   */
 100   if (ul_reason_being_called == DLL_PROCESS_ATTACH)
 101     do_libmain = (getenv("LIBMYSQL_DLLINIT") != NULL);
 102   if (do_libmain)
 103     return LibMain(hInst,ul_reason_being_called,lpReserved);
 104   return TRUE;
 105 }
 106
 107 #elif defined(WINDOWS)
 108
 109 /****************************************************************************
 110 **      This routine is called by LIBSTART.ASM at module load time.  All it
 111 **      does in this sample is remember the DLL module handle.  The module
 112 **      handle is needed if you want to do things like load stuff from the
 113 **      resource file (for instance string resources).
 114 ****************************************************************************/
 115
 116 int _export FAR PASCAL libmain(HANDLE hModule,short cbHeapSize,
 117                                UCHAR FAR *lszCmdLine)
 118 {
 119   s_hModule = hModule;
 120   libmysql_init();
 121   return TRUE;
 122 }
 123
 124 #endif